Inflammation-based Scores in Patients With Pheochromocytoma.

Background: Pheochromocytoma is associated with systemic inflammation but the underlying mechanisms are unclear. Therefore, we investigated the relationship between plasma metanephrine levels and hematological parameters-as a surrogate of inflammation-in patients with pheochromocytoma and the influence of preoperative α-blockade treatment.

Design and methods: We retrospectively studied 68 patients with pheochromocytoma who underwent adrenalectomy (median age, 53 years; 64.7% females) and 2 control groups matched for age, sex, and body mass index: 68 patients with nonfunctioning adrenocortical tumors and 53 with essential hypertension. The complete blood count and several inflammation-based scores (neutrophil-to-lymphocyte ratio [NLR], platelet-to-lymphocyte ratio [PLR], lymphocyte-to-monocyte ratio [LMR], systemic-immune-inflammation index [SII], prognostic-nutrition index) were assessed in all patients and, in a subset of pheochromocytomas, after adrenalectomy (n = 26) and before and after preoperative α-blockade treatment (n = 29).

Results: A higher inflammatory state, as indicated by both complete blood count and inflammation-based scores, was observed in patients with pheochromocytoma compared with nonfunctioning adrenocortical tumors and essential hypertension. Plasma metanephrine levels showed a positive correlation with NLR (r = 0.4631), PLR (r = 0.3174), and SII (r = 0.3709) and a negative correlation with LMR (r = 0.4368) and prognostic-nutrition index (r = 0.3741), even after adjustment for age, sex, ethnicity, body mass index, and tumor size (except for PLR). After adrenalectomy, we observed a reduction in NLR (P = .001), PLR (P = .003), and SII (P = .004) and a concomitant increase in LMR (P = .0002). Similarly, α-blockade treatment led to a reduction in NLR (P = .007) and SII (P = .03).

Conclusion: Inflammation-based scores in patients with pheochromocytoma showed pro-inflammatory changes that correlated with plasma metanephrine levels and are ameliorated by adrenalectomy and α-blockade.